Inter alia U.S. Pat. No. 4,714,457 discloses a method of preparing coagulation factors, such as fibrinogen, fibronectin, factor VIII and factor XIII from blood by centrifuging a blood sample in such a manner that said sample is separated into a plasma fraction and a cell-containing fraction, said cell-containing fraction inter alia containing platelets (thrombocytes), white blood cells (leukocytes) and red blood cells (erythrocytes). The coagulation factors are subsequently extracted from the plasma fraction by way of for instance cryoprecipitation or by means of a precipitation-promoting agent, such as ethanol. The extract consists mainly of fibrinogen, and by adding a suitable enzyme, such as thrombine, it can be used as tissue glue for instance in connection with operation wounds. When combined with thrombine, the fibrinogen forms fibrin like in nature, said fibrin forming an insoluble network of fibre-like material, which in connection with a wound healing process forms a sort of tissue glue connecting the wound surfaces. Therefore, a concentrate of coagulation factors consisting mainly of fibrinogen has turned out to have an extremely favourable effect on healing of operation wounds.
According to the above U.S. patent specification the concentrate of coagulation factors is prepared by means of various bags, the various fractions being transferred to said bags during the various steps of the process. Such a system of bags is a so-called open system involving a risk of infection and contamination of the personnel.
PCT/DK87/00117 describes an apparatus rendering it possible to prepare a concentrate of coagulation factors from blood from a single person (autologue blood), i.e. the same person who is to use the prepared composition later on in connection with an operation, whereby the risk of dissemination is avoided. The apparatus presents a so-called closed system avoiding the risk of infection and contamination of the personnel. The apparatus comprises a plurality of syringes or containers interconnected by means of valves and loose tubings with the result that it is rather difficult to handle.